First, it could make it harder for Democrats to break GOP filibusters because Republicans may be even less willing to close off debate on legislation.

Story Continued Below

Even worse for Democrats, the tactics Reid employed to change a Senate precedent could make it easier for Republicans to justify using similar procedures to force simple-majority votes on hugely contentious issues, such as repealing Democratic priorities like health care reform and Wall Street regulations, Senate experts on both sides of the aisle said Friday.

The chaos began Thursday night when Senate Democrats voted 51-48 to effectively overturn the Senate parliamentarian on a ruling regarding amendments offered after the Senate invokes cloture — which shuts off debate. It was the first time in 11 years the parliamentarian had been voted down. While the rules in play are arcane, the impact could be significant — future Senate majorities may be encouraged to more regularly employ a similar procedure if their will is being blocked by the minority party on hot-button policy fights.

“Changing the precedence of the Senate is a big deal,” said Sen. Roy Blunt (R-Mo.).

The new precedent limits how senators can force a vote on amendments in the 30 hours of debate after a filibuster is defeated. During that time, senators can no longer ask to suspend the rules so their amendments can be considered, a process that ordinarily would have required two-thirds of the Senate’s support to succeed. Now only amendments that both parties agree to can be considered for a vote after a filibuster is defeated.

As a result, Republicans in the minority party may now be far less willing to break a filibuster if Reid does not allow their amendments for votes beforehand or allow them to shape the bill sufficiently to their liking.

“One of the obvious fallouts is that it will be tougher and tougher to get cloture,” said Marty Paone, who spent more than a decade in the critical position of Democratic secretary, serving as his caucus’ point person on the floor proceedings and the arcane rules of the Senate. It requires 60 votes to invoke cloture, which effectively limits debate and ends a filibuster.

Asked about the move employed by Reid to force a rules change, Paone said: “It’s a can of worms they took down off the shelf — it’s always been there. … Hopefully they’ll put it on the back shelf and forget about it again.”

The Constitution grants each house of Congress the right to create its own rules - but the Senate rarely changes its procedures, which are designed to protect the rights of the minority party. Changing the rules requires the support of two-thirds of the Senate, a very high hurdle to clear. But overturning the ruling of the presiding officer only requires a simple majority — which would then create a new precedent governing floor procedures.

It’s this lower threshold - and the potential for major changes that could ensue — that has some senators, aides and procedural experts worried about the potential repercussions.

“Every time somebody uses one of these tactics, then it reminds people that that’s a tactic that you can use – so it might used against you in the future,” said Don Ritchie, the Senate’s historian.

The fight erupted unexpectedly Thursday night after Democrats had grown frustrated at GOP demands to have a series of unrelated amendments considered to a Chinese currency bill that had overcome a filibuster and was on track for final passage. Reid and Senate Minority Leader Mitch McConnell (R-Ky.) had agreed to consider seven amendments, including one under a suspension of the rules on whether to bring up Obama’s original jobs plan that had turned off some moderate Democratic members because of its tax hikes.